In general, baffle elements are provided to separate wet parts from dryer parts. Usually, such elements have a disc or plate like shape. The main purpose of an expandable element is to “bridge”, a slot between the element and the wall of the car body (usually made of steel, aluminium or reinforced composites) so that a watertight compartment within the car body is obtained.
WO 2015/063151 A1 describes a baffle or reinforcement element for ceiling and/or reinforcing a cavity and a method for producing such a baffle or reinforcement element. The baffle or reinforcement element comprises a carrier element and an expandable element supported by the carrier element. In a first embodiment of WO 2015/063151 A1, the carrier element and a cover element define a profile forming a peripheral recess for receiving the expandable element. In another embodiment, the expandable element is arranged on an edge of the carrier element. In essence, WO 2015/063151 A1 discloses a simple structure for a baffle or reinforcement element which is easy to assemble, in particular manually. However, the noise reduction characteristics of such a baffle or reinforcement element could be improved.
Document EP 1 362 683 A2 describes a baffle element (baffle precursor) comprising two cellular plates with a foamable material arranged therebetween. The plates are joined by integrally molded hinges. Stops are provided on the plates to provide a gap of predetermined thickness between the plates when they are superimposed. The foamable material is arranged within the gap. The plates are provided with a series of holes. The foamable material fills the entire gap between the plates and penetrates through the holes of the plates, if heat is activated. The manufacturing method of document EP 1 362 683 A2 appears to be rather complex and expensive.
WO 2014/095620 A1 discloses an insulation element for the acoustic insulation of an opening and/or of a cavity in a vehicle or building, having a carrier element and an expandable material. The carrier element has a plurality of through-holes, wherein only one surface of the carrier element is covered at least partially with expandable material, and the expandable material at least partially fills the through-holes. The central idea of WO 2014/095620 A1 is to have only one surface of the carrier element covered with expandable material (in the original un-expanded state). However, the reinforcement properties of the insulation element of WO 2014/095620 A1 are not satisfying for a some applications. Also, the manufacturing method appears to be comparatively complex.
EP 2 542 403 B1 discloses a method of forming a composite laminate for providing sealing, baffling or reinforcement to a structure, wherein an epoxy-based expandable structural foam material is located onto a reinforcement layer to form the composite laminate. The reinforcement layer is provided by a thermoplastic film with a thickness of 0.18 mm. In EP 2 542 403 B1, in particular the noise reduction characteristics could be improved.